Device hub · Fitness rings · Desk research

Oura Ring 4

Ring 4 is the leftover Oura with the wide size run (4–15), 7.9 × ~2.88 mm titanium, typically 5–8 days, and the same paid membership app as Ring 5.

Disclosure: Affiliate programs are not enrolled yet. See Affiliate disclosure. This page is manufacturer desk research, not a hands-on test — see Methodology.

In short

Ring 4 is the leftover Oura with the wide size run (4–15), 7.9 × ~2.88 mm titanium, typically 5–8 days, and the same paid membership app as Ring 5. Buy it for extreme sizes or leftover price. Skip it if you fit 6–13 and want the smaller Ring 5, or if you will not pay membership.

Who it is for

  • Buyers who need sizes 4–5 or 14–15, which Ring 5 does not sell.
  • People who want leftover Ring 4 pricing while Oura still lists it.
  • Existing Oura members — membership is account-tied and continues on Ring 4.
  • Anyone who prefers the recessed 0.3 mm sensor dome vs Ring 5’s 0.7 mm dome.

Who should skip it

  • Shoppers who fit 6–13 and want the smaller 6.09 × 2.28 mm Ring 5.
  • Anyone who will not pay Oura Membership after the complimentary month.
  • Buyers who specifically want Ring 4 Ceramic (zirconia, 3.51 mm, 5.1–8.1 g) — that is a different hub.
  • People who need a no-subscription 10–14 day ring.

Key differentiators

  • Widest current Oura size run: 4–15.
  • Smart Sensing + recessed sensors; up to 7 days of onboard memory (vs 3 on Ring 5).
  • Same membership feature list as Ring 5.
  • Typically 5–8 days; charge typically 20–80 minutes.

Caveats

  • Finish and size availability “may vary by current inventory” (Oura support, 18 June 2026). Date the store.
  • Sizing kit is not the Ring 5 kit.
  • No hands-on testing. Battery and Smart Sensing accuracy lines are Oura claims.
  • Oura Ring is not a medical device (General FAQs / Product Safety, 2026).
  • This environment can flip Oura geo. 2026-09-19: morning US-facing leftover from $349; one evening pull showed from €265.30; a later evening re-pull showed US dollars again (from $349); a 4:20 PM ET re-pull flipped /store to euros again (from €265.30); a ~4:45 PM ET re-pull showed US dollars again (from $349). US price cells stay on the same-day USD grid. Date the shop you opened.

Ring-category specs

Same rows on every ring page (Oura, Ultrahuman, RingConn, Galaxy Ring, Circular).

Oura Ring 4 — key specs
AttributeValueSource / note
MaterialsTitanium exterior and interior with PVD or DLC depending on finish; non-allergenic BPA-free titanium inner shellOura Ring 4 support
Width7.9 mmOura Ring 4 support compare table
Thickness~2.88 mm; recessed sensor dome 0.3 mmOura Ring 4 support
Weight3.3–5.2 g depending on size (titanium SKU)Oura Ring 4 support
Sizes4–15 (Ring 4 sizing kit)Oura Ring 4 support
FinishesStore still listed Gold, Silver, Stealth on 2026-09-19; confirm live inventoryouraring.com/store
Battery (OEM)Typically 5–8 daysOura Ring 4 supportOura: varies by size, settings, activity, battery age.
Charging (OEM)Typically 20–80 minutes depending on starting chargeOura Ring 4 support
Charging case (OEM)Size-specific charging dock + USB cable in the box (General FAQs). Not a Ring 5 travel case.Oura General FAQs 2026-09-18; Use Your Oura Ring Charger
Water resistance100 m / 328 ft. Ring 4 support: sauna and water sports, not diving. General FAQs / Product Safety (updated 2026-09-18): showering, swimming, recreational diving/snorkeling OK; not scuba; do not keep submerged over 12 hours.Oura Ring 4 support; General FAQs 2026-09-18; Product SafetyCite the page. Do not flatten “not diving” over the General FAQs recreational-diving sentence.
SensorsSmart Sensing; 3 photodetectors + 2 triple LEDs (red, green, IR); digital temperature; accelerometerOura Ring 4 support
Sleep trackingDetailed sleep analysis with membership; nighttime SpO2 via red + IROura Ring 4 support
Activity / fitness24/7 HR; Automatic Activity Detection; dynamic activity goals (membership)Oura Ring 4 support
AppOura AppOura Ring 4 support
Subscription / data accessOura Membership (US $5.99/mo or $69.99/year; 1 complimentary month for new members). Same account rules as Ring 5.Oura Membership support; Ring 4 support
Phone platformsiOS 16+ or Android 11+ with Google Play; Bluetooth 5.0 phoneOura Set up the Oura App / General FAQs
WirelessBluetooth Low Energy (Bluetooth Smart); EMF-safe; Airplane Mode; FCC certifiedOura Ring 4 support
On-ring storageUp to one week (seven days)Oura Ring 5 support compare table (Ring 4 column)
US price (dated)From $349 (Silver/Stealth) on ouraring.com/store, 2026-09-19ouraring.com/store
Price bandLeftover flagship membership ringDerived from dated US store
AnnouncedPrevious current generation; support last updated 18 June 2026Oura Ring 4 support
AvailabilityStill listed on the Oura store 2026-09-19; Oura says check store or authorized retailer for inventoryOura Ring 4 support; store

Oura Ring 4 extras

Unique to this line or SKU. Other rings keep the first table aligned and swap this extras list.

Oura Ring 4 extras
AttributeValueSource / note
Smart SensingOura’s named platform: algorithm adapts to finger structure, skin tone, and activity while managing battery. OEM claim, not our measurement.Oura Ring 4 support
Ring 4 Ceramic (not this SKU)Zirconia exterior, same sensing; 7.9 × 3.51 mm; 5.1–8.1 g. Hub: /rings/oura-ring-4-ceramic/Oura Ring 4 support compare table
Sizing kitRing 4 kit: white sizers 4–15. Not the Ring 5 6–13 kit.Oura Ring 4 support
Operating temperatureRing 4 support: −10–54 °C / 14–129 °F. General FAQs / Product Safety: −10–52 °C / 14–125 °F. Charge at room temperature.Oura Ring 4 support; General FAQs; Product SafetyCite the page. Do not average 54 and 52.
Latest listed firmware2.12.0 (17 June 2026) — internal optimizations and bug fixes. Firmware article last updated 17 June 2026; no newer Ring 4 build on the 2026-09-19 evening re-pull.Oura Device Firmware Versions 2026-06-17

Overview

Ring 4 is the leftover full-size Oura: 7.9 × ~2.88 mm titanium, recessed sensors, sizes 4–15, typically 5–8 days. Membership software is the same family as Ring 5.

Sensors, sleep, and activity

Smart Sensing, 3 photodetectors, red/green/IR LEDs, temperature, accelerometer. Membership unlocks the same sleep / HR / Stress / Heart Health / Women’s Health list as Ring 5.

Battery and charging

Typically 5–8 days; 20–80 minutes to charge. Up to 7 days of onboard memory — the main offline advantage versus Ring 5’s 3-day buffer.

App, subscription, and platforms

Oura App, iOS 16+ / Android 11+, US membership $5.99 / mo or $69.99 / year (support, 8 September 2026).

Price

US store 2026-09-19: from $349. Re-check before quoting a street ticket.

Sources

Frequently asked questions

Is Ring 4 discontinued?

Not on the store we opened. Oura still lists Ring 4 and Ring 4 Ceramic. Support says availability varies by inventory — treat it as leftover, not as the current flagship.

Does Ring 4 need membership?

Yes, for full app function — same account-tied membership as Ring 5. Gen2 is the generation Oura says does not require membership.

Can I use a Ring 5 sizing kit?

No. Oura labels kits by generation. Ring 4 is 4–15; Ring 5 is 6–13 and “slightly different.”

Is Ceramic the same ring?

Same Smart Sensing, different shell: zirconia, 3.51 mm thick, 5.1–8.1 g. Do not reuse this hub’s 2.88 mm / 3.3–5.2 g cells for Ceramic.

Official product page: Oura Ring 4. Specs: Oura Ring 4 specs.